This application relates to the art of bearings and, more particularly, to bearing lubrication. The invention is particularly applicable to a cartridge bearing and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and can be used in any environment where metered lubricant flow is desired across an interface passage between two joined surfaces that do not move relative to one another.
Bearing cartridges may have a lubricant reservoir from which lubricant is metered at a very slow controlled rate to maintain a lubricant film on the bearing rolling elements and raceways. In one arrangement, the passages through which oil is metered are formed at interfaces between overlapping cylindrical surfaces of reservoir housing members that are secured together within an interference fit. Many different arrangements have been attempted for configuring the surfaces at the interface to insure a desired lubricant flow rate. If the flow rate is too slow or the passages become clogged, the bearing may overheat and fail. If the flow rate is too fast, the lubricant will be exhausted and the bearing may fail before the expiration of its intended design life. Excessive lubricant also is undesirable because it increases torque requirements on the bearing to overcome churning losses. By way of example, the surfaces at the interface have been roughened and etched to provide capillary-like passages for the flow of lubricant. However, such arrangements are difficult to reproduce accurately in mass production and the reject rate is high when lubricators are tested to insure that they meet the design flow rate before assembly into a finished bearing.
It would be desirable to have such a bearing lubricator with an interface passage that is configured to provide accurate and reliable flow of lubricant from the reservoir to the rolling elements and raceways, and that can be accurately reproduced in mass production with minimal rejects.